Lars Engebretsen

Publications (133)360.27 Total impact

• Article: Sports injuries and illnesses during the London Summer Olympic Games 2012.

  Lars Engebretsen, Torbjørn Soligard, Kathrin Steffen, Juan Manuel Alonso, Mark Aubry, Richard Budgett, Jiri Dvorak, Manikavasagam Jegathesan, Willem H Meeuwisse, Margo Mountjoy, Debbie Palmer-Green, Ivor Vanhegan, Per A Renström
  [show abstract] [hide abstract]
  ABSTRACT: BACKGROUND: The Olympic Movement Medical Code encourages all stakeholders to ensure that sport is practised without danger to the health of the athletes. Systematic surveillance of injuries and illnesses is the foundation for developing preventive measures in sport. AIM: To analyse the injuries and illnesses that occurred during the Games of the XXX Olympiad, held in London in 2012. METHODS: We recorded the daily occurrence (or non-occurrence) of injuries and illnesses (1) through the reporting of all National Olympic Committee (NOC) medical teams and (2) in the polyclinic and medical venues by the London Organising Committee of the Olympic and Paralympic Games' (LOCOG) medical staff. RESULTS: In total, 10 568 athletes (4676 women and 5892 men) from 204 NOCs participated in the study. NOC and LOCOG medical staff reported 1361 injuries and 758 illnesses, equalling incidences of 128.8 injuries and 71.7 illnesses per 1000 athletes. Altogether, 11% and 7% of the athletes incurred at least one injury or illness, respectively. The risk of an athlete being injured was the highest in taekwondo, football, BMX, handball, mountain bike, athletics, weightlifting, hockey and badminton, and the lowest in archery, canoe slalom and sprint, track cycling, rowing, shooting and equestrian. 35% of the injuries were expected to prevent the athlete from participating during competition or training. Women suffered 60% more illnesses than men (86.0 vs 53.3 illnesses per 1000 athletes). The rate of illness was the highest in athletics, beach volleyball, football, sailing, synchronised swimming and taekwondo. A total of 310 illnesses (41%) affected the respiratory system and the most common cause of illness was infection (n=347, 46%). CONCLUSIONS: At least 11% of the athletes incurred an injury during the games and 7% of the athletes' an illness. The incidence of injuries and illnesses varied substantially among sports. Future initiatives should include the development of preventive measures tailored for each specific sport and the continued focus among sport bodies to institute and further develop scientific injury and illness surveillance systems.
  British journal of sports medicine 03/2013; · 2.55 Impact Factor
• Article: Functional outcomes following a non-operative treatment algorithm for anterior cruciate ligament injuries in skeletally immature children 12 years and younger. A prospective cohort with 2 years follow-up.

  Håvard Moksnes, Lars Engebretsen, Ingrid Eitzen, May Arna Risberg
  [show abstract] [hide abstract]
  ABSTRACT: BACKGROUND: The methodological quality of studies on treatment of anterior cruciate ligament (ACL) injuries in skeletally immature children after ACL injury is low, and no prospective studies have evaluated the functional outcomes following a non-operative treatment algorithm. PURPOSE: To report changes in knee function and activity level in skeletally immature children following a non-operative treatment algorithm for a minimum of 2 years after ACL injury. STUDY DESIGN: Prospective cohort. METHODS: 46 skeletally immature children aged 12 years and younger were evaluated at baseline and subsequent yearly follow-ups using patient-reported outcome measurements, isokinetic muscle strength measurements, single-legged hop tests and clinical examinations over a minimum period of 2 years. Participation in physical activities was monitored using a monthly online activity survey, and the main leisure-time sport activity was registered at the yearly follow-ups. RESULTS: 36 (78%) of the children did not undergo an ACL reconstruction during the follow-up. Statistically significant changes with questionable clinical relevance were discovered with the patient-reported outcome measurements or hop tests. Leg symmetry indexes were consistently above 90% for muscle strength and single legged hop tests throughout the study, and the isokinetic muscle strength improved significantly in the injured limb. Ninety-one per cent maintained participation in pivoting sports and/or physical education in school, although 38% of the ACL deficient children changed their main activity from a level 1 to a level 2 activity. CONCLUSIONS: A non-operative treatment algorithm may be appropriate for ACL injured skeletally immature children, although a reduced participation in level 1 activities may be necessary for some children.
  British journal of sports medicine 02/2013; · 2.55 Impact Factor
• Article: Biomechanical Comparison of Interference Screws and Combination Screw and Sheath Devices for Soft Tissue Anterior Cruciate Ligament Reconstruction on the Tibial Side.

  Cathrine Aga, Matthew T Rasmussen, Sean D Smith, Kyle S Jansson, Robert F Laprade, Lars Engebretsen, Coen A Wijdicks
  [show abstract] [hide abstract]
  ABSTRACT: BACKGROUND:The tibial fixation site has been reported to be the weakest point in anterior cruciate ligament (ACL) reconstructions. Numerous interference screws and combination screw and sheath devices are available for soft tissue fixation, and a biomechanical comparison of these devices is necessary. HYPOTHESIS:Combination screw and sheath devices would provide superior soft tissue fixation properties compared with interference screws in a porcine model. STUDY DESIGN:Controlled laboratory study. METHODS:Eight different intratunnel tibial soft tissue fixation devices were biomechanically tested in a porcine model with bovine tendons, with 10 specimens per group. The soft tissue fixation devices included 3 interference screws-the Bio-Interference Screw, BIOSURE PK, and RCI Screw-and 5 combination screw and sheath devices (combination devices)-the AperFix II, BIOSURE SYNC, ExoShape, GraftBolt, and INTRAFIX. The specimens were subjected to cyclic (1000 cycles, 50-250 N, 0.5 Hz) and pull-to-failure loading (50 mm/min) with a dynamic tensile testing machine. Ultimate failure load (N), cyclic displacement (mm), pull-out stiffness (N/mm), displacement at failure (mm), load at 3 mm displacement (N), and mechanism of failure were recorded. RESULTS:The ultimate failure loads were highest for the GraftBolt (1136 ± 115.6 N), followed by the INTRAFIX (1127 ± 155.0 N), AperFix II (1122 ± 182.9 N), BIOSURE PK (990.8 ± 182.1 N), Bio-Interference Screw (973.3 ± 95.82 N), BIOSURE SYNC (829.5 ± 172.4 N), RCI Screw (817.7 ± 113.9 N), and ExoShape (814.7 ± 178.8 N). The AperFix II, GraftBolt, and INTRAFIX devices were significantly stronger than the BIOSURE SYNC, RCI Screw, and ExoShape. Although the 3 strongest devices were combination screw and sheath devices, no significant differences were observed between the ultimate failure strengths of the screw and combination devices when compared as groups. The least amount of cyclic displacement after 1000 cycles was observed for the GraftBolt (1.38 ± 0.27 mm), followed by the AperFix II (1.58 ± 0.21 mm), Bio-Interference Screw (1.61 ± 0.22 mm), INTRAFIX (1.63 ± 0.15 mm), ExoShape (1.68 ± 0.30 mm), BIOSURE PK (1.72 ± 0.29 mm), BIOSURE SYNC (1.92 ± 0.59 mm), and RCI Screw (1.97 ± 0.39 mm). The GraftBolt allowed significantly less displacement than did the BIOSURE SYNC and RCI Screw. Similarly, no significant differences were observed between the cyclic displacements of the screws and combination devices when compared as groups. CONCLUSION:The combination screw and sheath devices did not provide superior soft tissue fixation properties compared with the interference screws alone in a porcine model. Although the highest ultimate failure loads and least amounts of cyclic displacement were observed for combination devices, group comparisons of screw and combination devices did not result in any significant differences for ultimate failure load and cyclic displacement. CLINICAL RELEVANCE:It is important to consider that these results represent device performance in an in vitro animal model and are not directly transferrable to an in vivo clinical situation. The combination of a sheath and screw did not consistently result in improved fixation characteristics compared with interference screw fixation.
  The American journal of sports medicine 02/2013; · 3.61 Impact Factor
• Article: Effect of Meniscal and Focal Cartilage Lesions on Patient-Reported Outcome After Anterior Cruciate Ligament Reconstruction: A Nationwide Cohort Study From Norway and Sweden of 8476 Patients With 2-Year Follow-up.

  Jan Harald Røtterud, Einar A Sivertsen, Magnus Forssblad, Lars Engebretsen, Asbjørn Arøen
  [show abstract] [hide abstract]
  ABSTRACT: BACKGROUND:The effect of concomitant intra-articular injury on patient-reported outcome after anterior cruciate ligament (ACL) reconstruction is debated. PURPOSE:To evaluate the effect of meniscal and articular cartilage lesions on patient-reported outcome 2 years after ACL reconstruction. STUDY DESIGN:Cohort study (prognosis); Level of evidence, 2. METHODS:The study included all patients with primary, unilateral ACL reconstruction registered in the Norwegian and the Swedish National Knee Ligament Registry from 2005 through 2008 who had completed the Knee Injury and Osteoarthritis Outcome Score (KOOS) Knee-Related Quality of Life subscale at a 2-year follow-up (mean ± SD, 2.1 ± 0.2 years) after surgery (n = 8476). Multiple linear regression analyses were used to evaluate the associations between each KOOS subscale (Pain, Other Symptoms, Activities of Daily Living, Sport and Recreation Function, Knee-Related Quality of Life) as the measure for patient-reported outcome and meniscal and cartilage lesions. RESULTS:A total of 3674 (43%) patients had meniscal lesion(s), 1671 (20%) had partial-thickness (International Cartilage Repair Society [ICRS] grades 1-2) cartilage lesion(s), and 551 (7%) had full-thickness (ICRS grades 3-4) cartilage lesion(s). Multiple linear regression analyses detected no significant associations between meniscal lesions or partial-thickness cartilage lesions and the scores in any of the KOOS subscales at the 2-year follow-up. Full-thickness cartilage lesions were significantly associated with decreased scores in all of the KOOS subscales. CONCLUSION:Patients with concomitant full-thickness cartilage lesions reported worse outcome in all of the KOOS subscales compared with patients without cartilage lesions 2 years after ACL reconstruction. Meniscal lesions and partial-thickness cartilage lesions did not impair patient-reported outcome 2 years after ACL reconstruction.
  The American journal of sports medicine 01/2013; · 3.61 Impact Factor
• Article: Radiographic Landmarks for Tunnel Positioning in Posterior Cruciate Ligament Reconstructions.

  Adam M Johannsen, Colin J Anderson, Coen A Wijdicks, Lars Engebretsen, Robert F Laprade
  [show abstract] [hide abstract]
  ABSTRACT: BACKGROUND:Consistent radiographic guidelines for tunnel placement in single- or double-bundle posterior cruciate ligament (PCL) reconstructions are not well defined. Quantitative guidelines reporting the location of the individual PCL bundle attachments would aid in intraoperative tunnel placement and postoperative assessment of a PCL reconstruction. HYPOTHESIS:Consistent and reproducible measurements in relation to radiographic landmarks for the entire PCL and its individual bundle attachments are achievable. STUDY DESIGN:Controlled laboratory study. METHODS:The femoral and tibial PCL bundle attachment centers of 20 nonpaired fresh-frozen cadaveric knees were labeled using radio-opaque spheres and the attachment areas were labeled using barium sulfate. Anteroposterior (AP) and lateral radiographs of the femur and tibia were obtained, and measurements of the distances between the PCL bundle centers and landmarks were acquired. RESULTS:On the AP femur view, the anterolateral bundle (ALB) and posteromedial bundle (PMB) centers were 34.1 ± 3.0 mm and 29.2 ± 3.0 mm lateral to the most medial border of the medial femoral condyle, respectively. The lateral femur images revealed that the ALB center was 17.4 ± 1.7 mm and the PMB center was 23.9 ± 2.7 mm posteroproximal to a line perpendicular to the Blumensaat line that intersected the anterior margin of the medial femoral condyle cortex. Anteroposterior tibia images revealed that the ALB and PMB centers were located 0.2 ± 2.1 mm proximal and 4.9 ± 2.9 mm distal to the proximal joint line, respectively. The PCL attachment center was 1.6 ± 2.5 mm distal to the proximal joint line. On the lateral tibia view, the ALB center was 8.4 ± 1.8 mm, the PCL attachment center was 5.5 ± 1.7 mm, and the PMB center was 2.5 ± 1.5 mm superior to the champagne glass drop-off of the posterior tibia. CONCLUSION:Radiographic measurements from several clinically relevant views of the femur and tibia were reproducible with regard to the anatomic locations of the ALB and PMB centers. The measurements from the lateral femur and tibia views provided the most clinically pertinent radiographic measurements intraoperatively. CLINICAL RELEVANCE:This study established a set of clinically relevant radiographic guidelines for anatomic reconstruction of the PCL. The parameters set forth in this study can be used in both the intraoperative and postoperative settings for both single- and double-bundle PCL reconstructions.
  The American journal of sports medicine 11/2012; · 3.61 Impact Factor
• Article: Arthroscopically pertinent anatomy of the anterolateral and posteromedial bundles of the posterior cruciate ligament.

  Colin J Anderson, Connor G Ziegler, Coen A Wijdicks, Lars Engebretsen, Robert F Laprade
  [show abstract] [hide abstract]
  ABSTRACT: The clock-face method to identify the femoral posterior cruciate ligament (PCL) attachment has poor accuracy and reproducibility. Measurements of clinically relevant anatomic structures would provide more useful surgical guidance. The purpose of the present study was to describe the attachments of the anterolateral and posteromedial bundles of the PCL relative to relevant landmarks to assist with arthroscopic anatomic PCL reconstructions. Dissections were performed on twenty nonpaired fresh-frozen cadaveric knees. The distal articular cartilage margin of the intercondylar notch had a consistent shape conforming to the attachments of the anterolateral and posteromedial bundles. The mean distance (and standard deviation) between the femoral centers of the anterolateral and posteromedial bundles was 12.1 ± 1.3 mm. The distal margins of the anterolateral and posteromedial bundles were a mean of 1.5 ± 0.8 mm and 5.8 ± 1.7 mm proximal to the notch articular cartilage, respectively. On the tibia, the lateral plateau articular cartilage, the medial meniscus attachment, and an osseous ridge ("bundle ridge") separating the anterolateral and posteromedial bundles were important arthroscopic landmarks. The mean distance between the tibial centers of the anterolateral and posteromedial bundles was 8.9 ± 1.2 mm. The pertinent landmarks identified during arthroscopic PCL reconstruction consistently marked the borders of the attachments of the anterolateral and posteromedial bundles. To guide femoral tunnel placement, the centers of both bundles should be triangulated relative to the reported landmarks. Furthermore, the distal edge of the femoral anterolateral bundle should be placed adjacent to the articular cartilage, whereas the posteromedial bundle should be centered, on average, 8.6 mm proximal to the cartilage margin, just distal to the medial intercondylar ridge. On the tibia, the PCL tunnel should be placed just anterosuperior to the bundle ridge, with use of the lateral articular cartilage and medial meniscus attachment to guide placement. The results of the present study can assist with more anatomic tunnel placement during single and double-bundle PCL reconstructions. The results also suggest that two reconstruction tunnels are needed to reconstruct the broad femoral attachment, whereas one reconstruction tunnel should be investigated further for the compact tibial attachment.
  The Journal of Bone and Joint Surgery 11/2012; 94(21):1936-45. · 3.27 Impact Factor
• Article: Intraoperative findings and procedures in culturally and geographically different patient and surgeon populations.

  Lars-Petter Granan, Maria C S Inacio, Gregory B Maletis, Tadashi T Funahashi, Lars Engebretsen
  [show abstract] [hide abstract]
  ABSTRACT: Background and purpose Patient and implant registries are important clinical tools in monitoring and benchmarking quality of care. For comparisons amongst registries to be valid, a common data set with comparable definitions is necessary. In this study we compared the patients in the Norwegian Knee Ligament Registry (NKLR) and the Kaiser Permanente Anterior Cruciate Ligament Reconstruction Registry (KP ACLRR) with regard to intraarticular findings, procedures, and graft fixation characteristics reported by the operating surgeon for both primary and revision anterior cruciate ligament reconstructions (ACLRs). Methods We performed a cross-sectional comparison of the NKLR and KP ACLRR cohorts registered between 2005 and 2010. Aggregate-level data including patient characteristics (age, sex, and laterality), meniscal and cartilage injury patterns and corresponding treatment procedures, choice of graft, and fixation characteristics (type and component material) were shared between registries. Descriptive analyses were then conducted. Results During the study period, 11,217 ACLRs were registered in the NKLR and 11,050 were registered in the KP ACLRR. In the NKLR, hamstring autograft was used more (68% vs. 30%) for primary ACLRs and allograft was used less (0.2% vs. 41%) than in the KP ACLRR. The KP ACLRR reports more meniscal tears among both primary and revision ACLRs (63% and 50% vs. 49% and 36%). The NKLR reports less use of biodegradable fixation devices. Conclusions Baseline findings between the NKLR and the KP ACLRR were congruent regarding patient characteristics and most injury patterns, adding to the evidence that comparisons and collaborations between these registries will provide generalizable information to the international orthopedic community. The variation in the treatment, including graft and implant selection and meniscus procedures, between the 2 registries provides opportunities to explore the impact of treatment choices on the outcomes of ACLRs.
  Acta Orthopaedica 11/2012; · 2.17 Impact Factor
• Article: Increased levels of apoptosis and p53 in partial-thickness supraspinatus tendon tears.

  Kirsten Lundgreen, Oystein Lian, Alex Scott, Lars Engebretsen
  [show abstract] [hide abstract]
  ABSTRACT: PURPOSE: The role of apoptosis in the progression of rotator cuff tendinopathy remains poorly understood. In particular, the extent of apoptosis in the partially torn supraspinatus tendon has not been well examined. METHODS: Biopsies were obtained from nine partially torn supraspinatus tendons, from the matched intact subscapularis tendons, and from 10 reference subscapularis tendons. Immunohistochemistry was used to assess the density of apoptotic cells (activated caspase-3; Asp175), proliferation (Ki67), and p53 (M7001), a key protein involved in regulating cell death. The Bonar scale was used to evaluate tendon degeneration. RESULTS: The density of apoptotic tendon cells and the density of cells expressing p53 were significantly increased in both the partially torn supraspinatus tendons and in the matched subscapularis tendons, compared with uninjured reference tendons. The Bonar score revealed significant tendon degeneration in the partially torn supraspinatus tendons compared with both matched and reference subscapularis tendons. Tendon cell proliferation was significantly increased in the partially torn supraspinatus tendons compared with reference subscapularis tendons. CONCLUSIONS: Partial-thickness tears of the supraspinatus tendon demonstrated an increased density of apoptotic, p53+ tendon cells. The fact that apoptosis was accompanied by increased tendon cell proliferation suggests that apoptosis may be related to an ongoing injury-repair process. Increased tenocyte apoptosis may be a relatively early feature in rotator cuff tendinopathy and could represent a possible target for therapeutic intervention.
  Knee Surgery Sports Traumatology Arthroscopy 10/2012; · 2.21 Impact Factor
• Article: Single-Legged Hop Tests as Predictors of Self-Reported Knee Function After Anterior Cruciate Ligament Reconstruction: The Delaware-Oslo ACL Cohort Study.

  David Logerstedt, Hege Grindem, Andrew Lynch, Ingrid Eitzen, Lars Engebretsen, May Arna Risberg, Michael J Axe, Lynn Snyder-Mackler
  [show abstract] [hide abstract]
  ABSTRACT: Single-legged hop tests are commonly used functional performance measures that can capture limb asymmetries in patients after anterior cruciate ligament (ACL) reconstruction. Hop tests hold potential as predictive factors of self-reported knee function in individuals after ACL reconstruction. Single-legged hop tests conducted preoperatively would not and 6 months after ACL reconstruction would predict self-reported knee function (International Knee Documentation Committee [IKDC] 2000) 1 year after ACL reconstruction. Cohort study (prognosis); Level of evidence, 2. One hundred twenty patients who were treated with ACL reconstruction performed 4 single-legged hop tests preoperatively and 6 months after ACL reconstruction. Self-reported knee function within normal ranges was defined as IKDC 2000 scores greater than or equal to the age- and sex-specific normative 15th percentile score 1 year after surgery. Logistic regression analyses were performed to identify predictors of self-reported knee function within normal ranges. The area under the curve (AUC) from receiver operating characteristic curves was used as a measure of discriminative accuracy. Eighty-five patients completed single-legged hop tests 6 months after surgery and the 1-year follow-up with 68 patients classified as having self-reported knee function within normal ranges 1 year after reconstruction. The crossover hop and 6-m timed hop limb symmetry index (LSI) 6 months after ACL reconstruction were the strongest individual predictors of self-reported knee function (odds ratio, 1.09 and 1.10) and the only 2 tests in which the confidence intervals of the discriminatory accuracy (AUC) were above 0.5 (AUC = 0.68). Patients with knee function below normal ranges were over 5 times more likely of having a 6-m timed hop LSI lower than the 88% cutoff than those with knee function within normal ranges. Patients with knee function within normal ranges were 4 times more likely to have a crossover hop LSI greater than the 95% cutoff than those with knee function below normal ranges. No preoperative single-legged hop test predicted self-reported knee function within normal ranges 1 year after ACL reconstruction (all P > .353). Single-legged hop tests conducted 6 months after ACL reconstruction can predict the likelihood of successful and unsuccessful outcome 1 year after ACL reconstruction. Patients demonstrating less than the 88% cutoff score on the 6-m timed hop test at 6 months may benefit from targeted training to improve limb symmetry in an attempt to normalize function. Patients with minimal side-to-side differences on the crossover hop test at 6 months possibly will have good knee function at 1 year if they continue with their current training regimen. Preoperative single-legged hop tests are not able to predict postoperative outcomes.
  The American journal of sports medicine 08/2012; 40(10):2348-56. · 3.61 Impact Factor
• Article: The prevalence of patellofemoral osteoarthritis 12 years after anterior cruciate ligament reconstruction.

  Britt Elin Oiestad, Inger Holm, Lars Engebretsen, Arne Kristian Aune, Ragnhild Gunderson, May Arna Risberg
  [show abstract] [hide abstract]
  ABSTRACT: PURPOSE: To investigate the prevalence of patellofemoral osteoarthritis (OA) and to explore the association between radiographic patellofemoral OA and symptoms and function 12 years after anterior cruciate ligament (ACL) reconstruction. METHODS: The study participants (n = 221) were consecutively included at the time of an ACL reconstruction in the period from 1990 to 1997. Knee laxity (KT-1000), isokinetic quadriceps strength, triple jump, stair hop, and the Cincinnati knee score were measured 6 months, 1 year, 2 years, and 12 years after surgery. At the 12-year follow-up, visual analogue scale for pain, the Knee injury and Osteoarthritis Outcome Score, the Tegner activity scale, and radiographic examination (Kellgren and Lawrence score) were added. To analyse the association between patellofemoral OA, symptoms, and function, binary regression analyses presenting odds ratios and 95 % confidence intervals were used. The analyses were adjusted for age, gender, and body mass index. RESULTS: One hundred and eighty-one of the 221 subjects (82 %), including 76 females (42 %) and 105 males (58 %), were evaluated at the 12.3 ± 1.2-year follow-up. Mean age at the follow-up was 39.1 ± 8.7 years. Additional meniscal or chondral injuries at the time of reconstruction or during the follow-up period were detected in 116 subjects (64 %). Radiographic patellofemoral OA was found in 48 subjects (26 %), including 3 subjects with isolated patellofemoral OA (1.5 %). Those with patellofemoral OA were older, had more tibiofemoral OA, and had significantly more symptoms and impaired function compared with those without patellofemoral OA. CONCLUSIONS: Patellofemoral OA was found in 26 % 12 years after ACL reconstruction. Patellofemoral OA was associated with increased age, tibiofemoral OA, increased symptoms, and reduced function. It is of clinical importance to include functional and radiographic assessment of the patellofemoral joint in the examination of long-term consequences following an ACL reconstruction. LEVEL OF EVIDENCE: II.
  Knee Surgery Sports Traumatology Arthroscopy 08/2012; · 2.21 Impact Factor
• Article: An isolated rupture of the posterior cruciate ligament results in reduced preoperative knee function in comparison with an anterior cruciate ligament injury.

  Asbjørn Arøen, Einar Andreas Sivertsen, Christian Owesen, Lars Engebretsen, Lars Petter Granan
  [show abstract] [hide abstract]
  ABSTRACT: PURPOSE: To investigate differences in preoperative knee function (Knee Injury and Osteoarthritis Outcome Score, KOOS), the time period from injury to surgery, and associated injuries when comparing primary isolated posterior cruciate ligament (PCL) and primary anterior cruciate ligament (ACL) reconstructions. METHODS: Isolated primary ACL and PCL reconstructions registered in the Norwegian National Knee Ligament Registry from 2004 through 2010 were included (n = 71 primary PCLs and 9,649 primary ACLs). Linear regression analysis was used to evaluate the preoperative KOOS subscale values. RESULTS: The preoperative KOOS in the PCL group (n = 71) and ACL group (n = 9,649) was significantly different for the subscales symptoms (mean difference, -8.4; 95 % CI: -12.8 to -4.0), pain (mean difference, -15.9; 95 % CI: -20.3 to -11.4), activities of daily living (mean difference, -12.9; 95 % CI: -17.4 to -8.4), sport and recreation (mean difference, -15.9; 95 % CI: -22.6 to -9.3), and quality of life (mean difference, -7.9; 95 % CI: -12.4 to -3.5). The primary isolated PCL-reconstructed knees had a median time from injury to surgery of 21 months in comparison with 8 months for ACL injuries. The ACL-injured knees had more associated injuries (meniscus and full-thickness cartilage lesions) than the PCL-injured knees. CONCLUSION: Surgically treated knees with an isolated rupture of the PCL exhibited worse knee function preoperatively compared with knees with an isolated ACL injury; in addition, the delay to surgery was longer. Meniscal lesions were found more frequently in ACL-injured knees. LEVEL OF EVIDENCE: Prospective cohort study, evidence Level I.
  Knee Surgery Sports Traumatology Arthroscopy 07/2012; · 2.21 Impact Factor
• Article: The current evidence for treatment of ACL injuries in children is low: a systematic review.

  Håvard Moksnes, Lars Engebretsen, May Arna Risberg
  [show abstract] [hide abstract]
  ABSTRACT: There is no consensus on the management of anterior cruciate ligament (ACL) injuries in skeletally immature children, and the methodological quality of published studies is questionable. The transphyseal reconstructions, physeal-sparing reconstructions, and nonoperative treatment algorithms that are advocated have little support in the literature. The purpose of this study was to systematically review the methodological quality of the literature on the management of ACL injuries in skeletally immature children. We performed a literature search with use of PubMed to identify prospective or retrospective studies whose primary aim was to assess the outcome after operative or nonoperative treatment of ACL injuries in skeletally immature children. To be included in the analysis, a study had to have a mean duration of follow-up of at least two years and a minimum of ten children in the study had to be verified to be skeletally immature. The methodological quality of the included studies was evaluated with use of the Coleman Methodology Score. No randomized controlled trials, two prospective cohort studies, and twenty-nine retrospective studies met the inclusion criteria. The Coleman Methodology Score averaged 44.7 ± 9.2 out of 100 (range, 28 to 62). The methodological deficiencies were most evident with regard to the number of included children, the study design, and the description of rehabilitation protocols, outcome criteria, and outcome assessments. Caution is necessary when interpreting the results of studies on the treatment of ACL injuries in skeletally immature children because of widespread methodological deficiencies. There is a need for appropriately sized prospective studies and detailed descriptions of rehabilitation programs.
  The Journal of Bone and Joint Surgery 06/2012; 94(12):1112-9. · 3.27 Impact Factor
• Article: Health protection of the Olympic athlete.

  Kathrin Steffen, Torbjørn Soligard, Lars Engebretsen
  [show abstract] [hide abstract]
  ABSTRACT: Protection of the athletes' health is a clearly articulated objective of the International Olympic Committee. Longitudinal surveillance of injuries and illnesses can provide valuable data that may identify high-risk sports and disciplines. This is a foundation for introducing tailored preventive measures. During the XXIX Summer and XXI Winter Games, comprehensive injury and illness recording through the medical staff of the participating National Olympic Committees and the sports medicine clinics revealed that between 7% and 11% of all athletes incurred an injury or suffered from at least one occurrence of illness during the Games. The incidence of injuries and illnesses varied substantially between sports. In the future, risk factor and injury mechanism analyses in high-risk Olympic sports are essential to better direct injury-prevention strategies. Concomitantly, periodic health evaluations of athletes will be instrumental to optimise health protection.
  British journal of sports medicine 06/2012; 46(7):466-70. · 2.55 Impact Factor
• Source

  Available from: Lars-Petter Granan

  Article: Registration rate in the Norwegian Cruciate Ligament Register: large-volume hospitals perform better.

  Karianne Ytterstad, Lars-Petter Granan, Børge Ytterstad, Kjersti Steindal, Knut Andreas Fjeldsgaard, Ove Furnes, Lars Engebretsen
  [show abstract] [hide abstract]
  ABSTRACT: The Norwegian Cruciate Ligament Register (NCLR) was founded in 2004. The purpose of the NCLR is to provide representative and reliable data for future research. In this study we evaluated the development of the registration rate in the NCLR. The Norwegian Patient Register (NPR) and the electronic patient charts (EPCs) were used as reference data for public and private hospitals, respectively. Data were retrieved for all primary and revision anterior cruciate ligament (ACL) surgery during 2008-2009 in public hospitals and during 2008 in private hospitals. The NOMESCO classification of surgical procedures was used for identification of ACL surgeries. Public hospitals were divided into subgroups according to the annual number of operations in the NPR: small hospitals (< 30 operations) and large hospitals (≥ 30 operations). For the 2-year data extracted from public hospitals, 2,781 and 2,393 operations met the inclusion criteria according to the NPR and the NCLR, respectively, giving an average registration rate of 86% (95% CI: 0.85-0.87). The registration rate for small public hospitals was 69% (CI: 0.65-0.73), which was significantly less than for large public hospitals (89%, CI: 0.88-0.90; p < 0.001). In 2008, private hospitals reported 548 operations to the NCLR while 637 were found in the EPCs, giving a registration rate of 86% (CI: 0.83-0.89). In that year, the registration rate for public hospitals was 86%, which was similar to that for private hospitals. The NCLR registration rate for the period 2008-09 was similar in both 2008 and 2009, and is satisfactory for research. There is room for improvement of registration rates, particularly in hospitals with a small volume of ACL operations.
  Acta Orthopaedica 04/2012; 83(2):174-8. · 2.17 Impact Factor
• Article: Comparison of community-based ACL reconstruction registries in the U.S. and Norway.

  Gregory B Maletis, Lars-Petter Granan, Maria C S Inacio, Tadashi T Funahashi, Lars Engebretsen
  [show abstract] [hide abstract]
  ABSTRACT: Joint registries have demonstrated value as a resource for the study of large numbers of patients, providing the opportunity to study rare occurrences and identify early failures of surgical procedures. Anterior cruciate ligament (ACL) reconstruction registries have been established in Norway and the U.S. In this study, we compared the preoperative characteristics of the Norwegian National Knee Ligament Registry (NKLR) and the Kaiser Permanente Anterior Cruciate Ligament Reconstruction Registry (KP ACLRR) cohorts. A cross-sectional comparison of the NKLR and KP ACLRR cohorts registered between 2005 and 2010 was performed. Aggregate level data including preoperative patient characteristics, mechanisms of injury, preoperative Knee Injury and Osteoarthritis Outcome Score (KOOS), intraoperative findings, and adjusted revision rates were shared between the two registries, and a descriptive analysis was conducted. During the study period, 10,468 primary ACL reconstructions were entered in the NKLR and 10,394, in the KP ACLRR. The age at the time of surgery was similar between the two cohorts (twenty-seven years in the NKLR versus twenty-eight years in the KP ACLRR), although the KP ACLRR had a higher proportion of males (65% versus 58%, p < 0.001). The revision rate per follow-up year was 0.9% in the NKLR and 1.5% in the KP ACLRR. Soccer was the most common mechanism of injury in both registries (40.0% in the NKLR and 26.6% in the KP ACLRR). The preoperative KOOS was statistically different, but the difference was not clinically relevant (defined as a change of >10 points). A higher prevalence of meniscal tears was seen in the KP ACLRR (61% versus 49%, p < 0.001). Baseline findings are so congruent between the NKLR and the KP ACLRR cohorts that comparisons between these two registries will likely provide information to the orthopaedic community that can be generalized.
  The Journal of Bone and Joint Surgery 12/2011; 93 Suppl 3:31-6. · 3.27 Impact Factor
• Source

  Available from: Asbjørn Årøen

  Article: Patients with focal full-thickness cartilage lesions benefit less from ACL reconstruction at 2-5 years follow-up.

  Jan Harald Røtterud, May Arna Risberg, Lars Engebretsen, Asbjørn Årøen
  [show abstract] [hide abstract]
  ABSTRACT: To investigate differences in patient-reported outcome after anterior cruciate ligament (ACL) reconstruction between patients with and without a concomitant full-thickness cartilage lesion. 30 primary ACL-reconstructed patients with an isolated concomitant full-thickness cartilage lesion and 59 matched controls without cartilage lesions were identified in the Norwegian National Knee Ligament Registry and included in the present study. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was used as the outcome measure. At a median follow-up of 2.1 years (range, 2-5 years) after ACL reconstruction, 80 (90%) of the patients completed the KOOS. Preoperatively, there were no differences in KOOS between the study group and the control group. At follow-up, patients with full-thickness cartilage lesions reported significantly decreased scores compared to patients without cartilage lesions in the KOOS subscales pain (mean difference, 8.1; 95% confidence interval [CI], 0.8-15.3), activities in daily living (mean difference, 5.8; 95% CI, 0.3-11.2), sport/recreation (mean difference, 19.8; 95% CI, 5.3-34.3) and quality of life (mean difference, 17.2; 95% CI, 4.2-30.1). Patients with full-thickness cartilage lesions reported significantly less improvement from preoperative to follow-up than patients without cartilage lesions for the KOOS subscales pain (mean difference, 11.6; 95% CI, 3.2-19.9), sport/recreation (mean difference, 20.6; 95% CI, 8.1-33.1) and quality of life (mean difference, 16.3; 95% CI, 3.8-28.7). ACL-injured patients with full-thickness cartilage lesions reported worse outcomes and less improvement after ACL reconstruction than those without cartilage lesions at 2-5 years follow-up. Prognostic; prospective cohort study, Level I.
  Knee Surgery Sports Traumatology Arthroscopy 11/2011; 20(8):1533-9. · 2.21 Impact Factor
• Article: Evaluation of a simulated pivot shift test: a biomechanical study.

  Lars Engebretsen, Coen A Wijdicks, Colin J Anderson, Benjamin Westerhaus, Robert F LaPrade
  [show abstract] [hide abstract]
  ABSTRACT: Double-bundle anterior cruciate reconstructions have led to an increased interest in quantifying anterolateral rotatory stability. The application of combined internal rotation and valgus torques to the knee can more nearly recreate the anterolateral subluxation that occurs in the pivot shift test in vitro compared to coupled internal rotation torque and anterior tibial loads. Twelve non-paired cadaveric knees were biomechanically tested with the ACL intact and sectioned. For each test state, six-degree-of-freedom positional data were collected for two simulated pivot shift loads consisting of a 5-Nm internal rotation torque coupled with either a 10-Nm valgus torque or an 88 N anterior tibial load at 0°, 20°, 30°, 60°, and 90° of knee flexion. The coupled internal rotation and valgus torques produced a significant increase in anterolateral subluxation between the ACL intact and sectioned states at all tested angles except 90º (5.9 ± 0.4 mm at 0°, 4.3 ± 0.6 mm at 20°, 3.5 ± 0.6 mm at 30°, 2.1 ± 0.6 mm at 60°). The coupled internal rotation and an anterior tibial load produced significant increases between the ACL intact and sectioned states at all tested angles except 30º (5.4 ± 0.5 mm at 0°, 3.7 ± 0.5 mm at 20°, 2.1 ± 0.8 mm at 60°, 1.4 ± 0.3 mm at 90°). We found that the coupled internal rotation and valgus torques best recreated the anterolateral subluxation that occurs in the pivot shift in vitro. This study describes an anterolateral subluxation test for ACL integrity in the laboratory setting.
  Knee Surgery Sports Traumatology Arthroscopy 11/2011; 20(4):698-702. · 2.21 Impact Factor
• Article: Responsibility of sport and exercise medicine in preventing and managing chronic disease: applying our knowledge and skill is overdue.

  Gordon O Matheson, Martin Klügl, Jiri Dvorak, Lars Engebretsen, Willem H Meeuwisse, Martin Schwellnus, Steven N Blair, Willem van Mechelen, Wayne Derman, Mats Börjesson, Fredrik Bendiksen, Richard Weiler
  [show abstract] [hide abstract]
  ABSTRACT: The rapidly increasing burden of chronic disease is difficult to reconcile with the large, compelling body of literature that demonstrates the substantial preventive and therapeutic benefits of comprehensive lifestyle intervention, including physical activity, smoking cessation and healthy diet. Physical inactivity is now the fourth leading independent risk factor for death caused by non-communicable chronic disease. Although there have been efforts directed towards research, education and legislation, preventive efforts have been meager relative to the magnitude of the problem. The disparity between our scientific knowledge about chronic disease and practical implementation of preventive approaches now is one of the most urgent concerns in healthcare worldwide and threatens the collapse of our health systems unless extraordinary change takes place. The authors believe that there are several key factors contributing to the disparity. Reductionism has become the default approach for healthcare delivery, resulting in fragmentation rather than integration of services. This, in turn, has fostered a disease-based rather than a health-based model of care and has produced medical school curricula that no longer accurately reflect the actual burden of disease. Trying to 'fit' prevention into a disease-based approach has been largely unsuccessful because the fundamental tenets of preventive medicine are diametrically opposed to those of disease-based healthcare. A clinical discipline within medicine is needed to adopt disease prevention as its own reason for existence. Sport and exercise medicine is well positioned to champion the cause of prevention by promoting physical activity. This article puts forward a strong case for the immediate, increased involvement of clinical sport and exercise medicine in the prevention and treatment of chronic disease and offers specific recommendations for how this may begin.
  British journal of sports medicine 09/2011; 45(16):1272-82. · 2.55 Impact Factor
• Article: Management of anterior cruciate ligament injuries in skeletally immature individuals.

  Håvard Moksnes, Lars Engebretsen, May Arna Risberg
  [show abstract] [hide abstract]
  ABSTRACT: Anterior cruciate ligament (ACL) injuries in skeletally immature individuals remain a challenge for the child, the parents, orthopaedic surgeons, and physical therapists. The main challenges are the potential risk of recurrent instability, secondary injuries following nonoperative treatment, and the risks involved with surgical treatment due to the vulnerability of the epiphyseal growth plates. We first present the physiological background for considerations that must be made when advising on treatment alternatives for skeletally immature individuals after ACL injury. The implications of continuous musculoskeletal development for treatment decisions are emphasized. No randomized controlled trials have been performed to investigate outcomes of different treatment algorithms. There is no consensus in the literature on clinical treatment decision criteria for whether a skeletally immature child should undergo transphyseal ACL reconstruction, physeal sparing ACL reconstruction, or nonoperative treatment. Additionally, well-described rehabilitation programs designed for either nonoperative treatment or postoperative rehabilitation have not been published. Based on the currently available evidence, we propose a treatment algorithm for the management of ACL injuries in skeletally immature individuals. Finally, we suggest directions for future prospective studies, which should include development of valid and reliable outcome measures and specific rehabilitation programs.
  The Journal of orthopaedic and sports physical therapy. 09/2011; 42(3):172-83.
• Article: Cartilage repair in the rabbit knee: mosaic plasty resulted in higher degree of tissue filling but affected subchondral bone more than microfracture technique: a blinded, randomized, controlled, long-term follow-up trial in 88 knees.

  Stig Heir, Asbjørn Årøen, Sverre Løken, Ingar Holme, Lars Engebretsen, Finn P Reinholt
  [show abstract] [hide abstract]
  ABSTRACT: Discrepancies and variances in outcome following different surgical techniques for cartilage repair are poorly understood. Successful repair relies on proper tissue filling without initiating degenerative processes in the cartilage-bone unit. Consequently, the objective of the current study was to compare two available techniques for cartilage repair, i.e., microfracture technique and mosaic plasty, regarding tissue filling and subchondral bone changes in an experimental model. A 4-mm pure chondral defect was created in the medial femoral condyle of both knees in New Zealand rabbits, aged 22 weeks. A stereomicroscope was used to optimize the preparation of the defects. In one knee (randomized), the defect was treated with microfracture technique whereas in the other with mosaic plasty. The animals were killed at 12, 24 and 36 weeks after surgery. Defect filling, new bone formation above the level of the tidemark and the density of subchondral mineralized tissue were estimated by histomorphometry. Mosaic plasty resulted in a significantly 34% higher degree of tissue filling than microfracture technique at 36 weeks, SD of mean difference being 34%. Mosaic plasty resulted in significantly more new bone formation and reduced subchondral mineralized tissue density compared to microfracture technique. The differences between the two techniques were apparent mainly at the long-term follow-up. Tissue filling is a limiting factor regarding microfracture technique when compared to mosaic plasty, whereas mosaic plasty resulted in more bone changes than microfracture technique-the implications of the latter remain to be settled. This study underlines the difficulty in predicting outcome in the single case with any of these two techniques, particularly in a long-term perspective.
  Knee Surgery Sports Traumatology Arthroscopy 09/2011; 20(2):197-209. · 2.21 Impact Factor